The invention relates to a sensor signal converter for machine tools and production machines, and, robots, hereinafter machines which generate pulsed signals from sensor values transmitted via a drive bus.
SIMOVERT MASTERDRIVES SLE/SLE-DP-SIMOLINK-Encoder, GWE-477 763 4070.76J, Siemens AG 2001 discloses an encoder which simulates sensor values on an electrical shaft and provides a central actual machine value (actual position value) which is generated from a reference nominal value. The SIMOLINK encoder generates two pulsed signals shifted through 90xc2x0 and a zero pulse from a nominal angle value transported by means of SIMOLINK (optical waveguide connection). These are made available to other appliances by the encoder via RS422. The encoder thus simulates a pulse sensor with selectable, programmable quantization intervals.
It is an object of the present invention to provide a sensor signal converter which can respectively receive, convert and forward sensor signals in real time. The present invention achieves this object as a result of 1) sensor signals being able to be transmitted on a drive bus in real time; 2) the signals being able to be converted into sensor-compatible pulsed signals by a sensor signal converter in real time; and 3) the signals being able to be sent to other appliances in real time. The novel design of the sensor signal converter enables appliances which are not compatible with the main drive bus, for example drives from different manufacturers, to be coupled on a drive technology basis by means of a sensor interface.
A preferred embodiment of the present invention is characterized in that a control computer generates synthetic nominal values for at least one signal sensor converter and/or at least one drive regulator. Thus, various process information and/or process stipulations can be used in a control computer to generate synthetic nominal values. These values can be changed according to program execution and/or process flow.
In another preferred embodiment of the invention, a control computer receives nominal values from at least one further automation component. Thus, nominal values can advantageously be sent from automation components to a sensor converter using a control computer, for example, a drive bus. In this context, the control computer can serve as conversion component if the automation component prescribing nominal values cannot be compatibly connected to the sensor converter. Similarly, nominal value corrections or alterations can be made in the control computer.
In yet another preferred embodiment of the invention, a real and a synthetic nominal value source is flexibly assigned to at least one sensor signal converter using a control computer and/or a drive regulator. Hence, nominal value sources can be arbitrarily assigned to sensor converters in the configuration phase of a technical installation.
In still another preferred embodiment of the invention, a real and a synthetic nominal value source is flexibly assigned during operation on the basis of a mode of operation and/or execution of a program and/or an instance of fault. In this way, nominal value sources can be flexibly assigned to sensor converters according to demand and requirement even during operation of a technical installation.
Preferably, a clock signal can be produced or derived in the sensor signal converter in synchronism with the communication clock of the input data link having real-time capability. Thus, clock generation or formation in the sensor signal converter takes place strictly in synchronism with the transmission clock.
It is preferred that the sensor signal converter is an integral part of a drive regulator. This means that integral system resources of the drive regulator can advantageously be used. This minimizes the hardware costs and the complexity of installation for appliances or drives. Further, at least one real-time data link which can be used for the drive regulator is an Ethernet which makes it possible to use a standardized bus protocol which can be used universally and permits a high transmission capacity. Short bus cycles allow data to be transmitted in the system with real-time capability, which permits nominal value discrepancies to be quickly corrected.